The proposed study will assess the relationship between exposure to industrial livestock operations and the prevalence of asthma-related symptoms among 7TH and 8TH grade students attending public schools in North Carolina. During the 1999-2000 school year, the North Carolina Department of Health and Human Services conducted a statewide population-based survey of middle school students in order to assess the prevalence of asthma-related symptoms, medication use, barriers to adequate medication use, and behavioral consequences of the reported symptoms. This application seeks to extend the benefit and utility of the statewide survey by exploring the relationship between the prevalence of asthma symptoms among surveyed students and exposure to agricultural airborne pollutants experienced during school hours. School-based exposure will be estimated using an extensive database of industrial livestock operations, including information about the size, type of animals, geographic location, and waste management practices. Exposure estimates will be supplemented with information provided about the school environment, including air-conditioning, mold, odor, and other school-building characteristics. Epidemiologic analyses will focus on the association between the prevalence of asthma-related symptoms and exposure estimates. The specific aims of this study are: (1) to estimate exposure to airborne emissions from industrial livestock operations at public middle schools using spatial analysis of the following measurements: (a) distance from the livestock operation to the middle school, (b) steady state live weight of all animals in livestock operations surrounding a given middle school, and (c) information obtained from school personnel about odor, environmental, and physical conditions at the schools; (2) to determine whether students' risk of asthma-related symptoms is related to the distance to the nearest industrial livestock operation, quantity of animals near the school, and school-based exposure to industrial livestock; and (3) to evaluate the distribution of asthma-related symptoms and exposures within geographic, racial, and socio-economic categories to determine whether the frequency and severity of symptoms and livestock exposures most heavily burden specific subpopulations of students.